FLH2 woes

[motorhead1991]

Let me start off by stating that LowRanger96 and I have already discussed this, and we're both stumped.

Now then, I have a 1990 Ranger being run by an FLH2 ECM with a Quarterhorse attached, and for whatever reason, neither of us know or can tell why it's not switching to open loop. I replaced the junkyard O2 sensor I had with a new Bosch sensor as well. His BE2012 also shows different values than my own, which further adds to the confusion. Attached isthe database I'm using. Logs will follow shortly.

running_4-2-17.BEB

[decipha]

we cant do anything with an encrypted .beb

[motorhead1991]

Ok, well I don't have an unencrypted version, so maybe you can explain what would cause the ECM to not switch. MAF curve is near dead on, HEGO is new and fluctuates between .001 and .008, never more. The truck runs great in OL, but won't switch.

[decipha]

the ecu starts out in open loop at key on, are you saying once it goes into closed loop it wont go back into open loop at high throttle? if so check fn320a the ect ol threshold and make sure it as well as fn035 is set accordingly in reference to prldsw

if its in open loop and doesnt switch in to closed loop then its either a condition isnt allowing it such as the hego minimum switches before cl is allowed or even one of the warm hego delay scalars could be maxed out, or it could be forcing open loop from a corrupt value

[motorhead1991]

I reset the KAM, via positive cable, with noticible results. KAMRF started fluctuating above 1, and it switched to CL. Whether or not I can repeat that is now the question. I plan on changing the HEGO settings back to their defaults and trying it again.

[motorhead1991]

Last update, then I'll consider this thread dead. The issue was the pinning in the '90 O2 extension, as it differs from the 95 O2 pinout. I simply repinned the plug, and all is well with fuel control.

I'm currently running Siemens 60# injectors on an NA motor, so I'm ready for the addition of a turbo.

[decipha]

excellent

[motorhead1991]

So I've figured out how to set idle spark (it hovers around 18°), but the RPM is up around 1200. Do I need to play with the ISC now? Should I do an idle reset as well?

Also, DSFO spark is locking at 18° as well, which is causing popping and occasional backfiring. I don't mind it, but my fiancee and probably my catalytic converter aren't fans of it. Is that also spark source 9?

[decipha]

idle spark is controlled the same way it is on all 94+ strategies, spark reserve is target not to exceed MBT, all the details are in the spark write up on the homepage

make sure the closed throttle flag is set and that iscdc is lowish < 35%, if so then go ahead and turn down the throttle stop to take some air out of her

[motorhead1991]

idle spark is controlled the same way it is on all 94+ strategies, spark reserve is target not to exceed MBT, all the details are in the spark write up on the homepage

make sure the closed throttle flag is set and that iscdc is lowish < 35%, if so then go ahead and turn down the throttle stop to take some air out of her

It seems like it idles at 19%, so I have some room to work on it.

MBT at idle goes as high as 24° I think, which again leaves me some wiggle room. I'll have to find its happy spot. These 2.3s are notoriously poor breathing, even with porting (I also changed its characteristics by cutting and polishing the combustion chamber).

I'll have to see at what spark time it's happiest and go from there.